Public Methods

Throws

Tries to read up to MAX_HEADER_LENGTH bytes from InputStream is and use read bytes to
determine type of the image contained in is. If provided input stream does not support mark,
then this method consumes data from is and it is not safe to read further bytes from is after
this method returns. Otherwise, if mark is supported, it will be used to preserve original
content of is.

Returns

ImageFormat matching content of is InputStream or UNKNOWN if no type is suitable